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Duality Invariance of Cosmological Perturbation Spectra

David Wands
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Abstract

I show that cosmological perturbation spectra produced from quantum fluctuations in massless or self-interacting scalar fields during an inflationary era remain invariant under a two parameter family of transformations of the homogeneous background fields. This relates slow-roll inflation models to solutions which may be far from the usual slow-roll limit. For example, a scale-invariant spectrum of perturbations in a minimally coupled, massless field can be produced by an exponential expansion with $a\propto e^{Ht}$, or by a collapsing universe with $a\propto (-t)^{2/3}$.

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BibTeXRIS

David Wands. 1999-04-21. Duality Invariance of Cosmological Perturbation Spectra. https://doi.org/10.1103/physrevd.60.023507

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